Naphthalene formation pathways from phenyl radical via vinyl radical (C<sub>2</sub>H<sub>3</sub>) and vinylacetylene (C<sub>4</sub>H<sub>4</sub>): computational studies on reaction mechanisms and kinetics
Bibliographic record
Abstract
The reaction mechanisms of PAH formation from phenyl radical (C 6 H 5 ) to naphthalene via C 2 H 3 (C 2 H 3 -Path) and C 4 H 4 (C 4 H 4 -Path) were investigated by the G3(MP2, CC) method. The hydrogen abstraction, ring closure, cis–trans isomerization, and disproportionation reactions were considered, as well as their occurred sequence. The results showed that H-abstraction reactions occurred more easily than H-dissociation reactions. The cis–trans conversion reactions in sub-routes of C 2 H 3 -Path and C 4 H 4 -Path provided the largest barriers of 51, 53, and 36 kcal/mol along their routes, which illustrated that the cis–trans isomerization was energetically costly in the PAH formation process. The entrance barriers of C 2 H 2 -Path, C 2 H 3 -Path, and C 4 H 4 -Path are 6, 8, and 3 kcal/mol, respectively, which indicates that it is easier to add C 4 H 4 to C 6 H 5 compared with adding C 2 H 2 to C 2 H 3 . C 2 H 3 additions were highly exothermic with reaction energies greater than 110 kcal/mol, and compared with C 2 H 2 additions, C 2 H 3 additions were irreversible. However, C 2 H 2 -Path, C 2 H 3 -Path and C 4 H 4 -Path involved energy barriers of 20, 32, and 36 kcal/mol, respectively. Considering the high temperature in combustion and the approximate concentrations of C 2 H 3 and C 4 H 4 , all three of these pathways could lead to naphthalene in some combustion flames.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".